Gun barrel built of an a-tube and a breech piece



1 ,404,558. Patented Jan. 24, 1922.

J. VOLLMER= GUN BARREL BUILT OF AN A-TUBE AND A BREECH PIECE.

A P P L l C A T I 0 N F L E D l U N E 6 l 9 2 l- 3 b F A 5 r k b JOHNVOLLMER, OF ESSEN, GERMANY,

GUN BARREL BUILT OF AN A-TUBE A BREECH PIECE.

Specification of Letters Patent Patented Jan. 241; 1922.

Original application filed December 3, 1920, Serial No. 428,086. Dividedand this application filed June T 0 all whom it may concern:

Be it known that I, JOHN VOLLMER, residing at Essen, Germany, a citizenof the German Republic, have invented a certain new and usefulImprovement in a Gun Barrel Built of an A-tube and a Breech Piece, forwhich I have filed an application in Germany dated May 31, 1917, and ofwhich the following is a specification.

My invention relates to gun barrels built of an, A-tube and abreech-piece. The breech-piece is formed with a jacket portion whichscrew threadedly engages the A-tube.

This application is a division of my copending application, Serial No. 7428,086, filed December 3rd, 1920. p

The object of this invention is to provide such a connection betweenthese two parts of the gun barrel as will contain sutlicient' resistanceto the stresses set up upon firing, with as little weight as possiblewith the connecting parts, at the same time effectually sealing thejoint between the composite parts of the gun barrel.

The various features of the invention will be more clearly described andillustrated in the accompanying drawings in which:

Fig. 1 is a longitudinal section of a portion of a gun barrelconstructed in accordance with my invention, and

Fig. 2 is atransverse section on line2-2 of Fig. 1.

The gun barrel consists of a double A- tube A A and a breech-piece Thebreech-piece is formed with a acket portion 7) which envelopes the rearportion of the A-tube.

The connection between the breech-piece and the Atube is obtained byscrew-threaded engagement between the two and for this purpose the layerA of the A-tube is provided with screw-threads a and the jacket portion6' is provided with corresponding screw-threads 6 The breech-piece isprovided with a slot 6 to accommodate the breech-block and a loadingaperture 6 Serial No. 475,393.

In order that breech-piece and A-tube, to enable the connection to beput under the proper tension, the extensions a are made of such a lengththat they stop. short of the face 12 of the breech-piece when thebreech-piece assumes its correct position relative to the A-tube.

The breech-piece is provided with undercut grooves b to accommodatecovering strips F which strips are adapted to close the stresses orintervals E left between the extension a and the faces 5 These strips Frun parallel to the front face of the breech-slot and bear against therear face a of the liner A. These strips are so disposed that theycannot protrude into the breeclrslot and endwise motion of the strips Fis prevented in screws G. These strips prevent the entrance of dirt intothe intervals E and effectually prevent the liner A from setting backinto the breech-slot b Owing to the fact that the wall b of the jacketportion 5, instead of making a sharp or slightly rounded angle with theface 6 is sloped off into the latter with an arc struck with a longradius, the A-tube is permitted to retain its full diameter right up toits rear face. This structure offers great resistance for thebreech-piece to cracking at the dangerous section where the wall I)merges into: the face 6 and suflicient strength to the A-tube up to itsrear end to prevent expansion under pressure of the powder gases,together also with the least weight possible of the parts in question.

Having thus described my invention, what I claim is:

1. A composite gun barrel comprising a breech-piece and an A-tube, saidbreech piece being provided with a screw-threaded bore for the receptionof the end of the A-tube, the' rear face of said bore being arc-shapedextensions formed on the rear end of the A-tube corresponding in shapeto the arc-shaped rear faces of the bore and of such length as to leavea space between the rear face of the bore and said extensions andseparate covering strips running parallel to the front face of thebreech-slot, as and for the purpose described.

2. A composite gun barrel comprising a breech-piece and an A-tubecomprising an outer member and a liner, said breechpiece being providedwith a bore for the reception of the A-tube, the cylindrical wall of thesaid bore being'sloped off into the rear face of the said bore by an arcstruck with a large radius, the said slope commencing at a point in therear of the end face of the liner of the A-tubev and filler pieces inthe rear portion of the bore of the breech-piece, said filler piecesbeing formed by extensions on the A-tube.

3. A composite gun barrel comprising a: breech-piece and an A-tubecomprising an outer member and" a liner, said breechpiece being providedwith a bore for the reception of the A-tube, the cylindrical wall ofsaid bore being sloped off into the rear face of the said bore-by an arcstruck with a large radius, the said slope commencing at a point in therear of the end face of the liner of the A-tube-and filler pieces in therear portion of the bore of the breech-piece, said filler pieces leavingspaces between them and the rear face of the bore of the breech-piece, awedge-slot in said breechpiece and strips covering said spaces towardssaid wedge-slot and running parallel to the front face of saidWedge-slot.

A composite gun barrel comprising a breech-piece and an A-tubecomprising an outer member and a liner, said breech-piece being providedWith a bore for the reception of the A-tube, the cylindrical Wall ofsaid bore being sloped 01f into the rear face of the said bore by an.arc struck with a large radius the saidslope commencing at a point inthe'rear of the end face of the liner of the A-tube and filler pieces inthe rear portion of the bore of the breech-piece said filler piecesbeing formed by extensions on the A-tube, said extensions leaving spacesbetween them and the rear face of the bore of the breech-piece, a

wedge-slot in said breech-piece and strips covering said spaces towardssaid Wedgeslot and running parallel to the front face of saidwedge-slot.

The foregoing specification signed at Essen, Germany, this 21st day ofApril, 1921. i

JOHN VOLLMER.

